Atrial natriuretic peptide predicts impaired atrial remodeling and occurrence of late postoperative atrial fibrillation after surgery for symptomatic aortic stenosis

BACKGROUND: Aortic stenosis (AS) and atrial fibrillation (AF) are commonly encountered in clinical practice. Natriuretic peptides (NP) are endogenous cardiac hormones, which have been shown to increase in patients with heart failure, and valvular or congenital heart disease. We aimed to determine the association between atrial NP (ANP) and late postoperative AF after surgery for AS along with temporal changes in plasma ANP levels and left atrial (LA) volumes. METHODS: 22 patients (16 males/6 females, mean age: 61 years) with symptomatic AS and 8 healthy volunteers (5 males/3 females) were enrolled into our study. All the patients studied underwent transthoracic echocardiography, which was repeated during the follow-up. N-terminal ANP (N-ANP) was studied initially and at the 2-month follow-up. Postoperatively, the patients were followed up for 12 months for AF attacks. RESULTS: Patients with AS had significantly higher levels of N-ANP, left ventricular (LV) end-diastolic pressure, E/A ratio, LV mass and LA volumes compared to the controls. Patients with postoperative AF attacks were significantly older, had higher N-ANP levels and LV end-diastolic pressure in addition to higher LA volumes and longer symptom duration compared to patients without AF. Age at the time of operation (p = 0.011) and N-ANP at the 2nd month (p = 0.047) were found to be independent predictors for late AF attacks during follow-up in regression analysis. Besides, N-ANP (p < 0.001) at the 2-month follow-up independently predicted impaired LA remodeling. CONCLUSION: ANP might be an important factor to identify AS patients at risk for late postoperative AF attacks.     

Effects of sevoflurane on QT dispersion and heart rate variability

The purpose of this study was to use estimates of corrected QT dispersion (QTcd) and heart rate variability (HRV) to assess the effects of sevoflurane, an inhalation agent used frequently in clinical practice, on autonomic cardiac function. This study was conducted prospectively and in a blind manner on 20 women between 38 and 51 y of age who were classified as American Society of Anesthesiologists stage I–II and whose treatment required total abdominal hysterectomy. Electrocardiograms were recorded by 12-lead Holter monitor for 5 min before sevoflurane induction and again for 5 min at 10 min after tracheal intubation. Data on the first recording were considered as baseline; those on the second recording were viewed as final data. The study was terminated at this point, and surgery was allowed to proceed. QTcd and HRV values were assessed by a cardiologist, who was blinded to all data. All parameters were expressed as a mean value ± standard deviation. Wilcoxon’s test was used to compare baseline and final data. Statistical significance was considered asP< .05. No significant changes were observed between baseline and final QTcd values and between low and high-frequency components (LF and HF) of HRV; nor were changes seen in the LF/HF ratio. With the patient under sevoflurane/nitrous oxide anesthesia, no significant changes were detected in QTcd, LF, and HF values, and in the LF/HF ratio, whereas a significant increase (P=.001) was seen in standard deviation of the R-R interval, which was used as a measure of cardiac autonomic tone.     

Revisiting secondary amyloidosis for an inadequately investigated feature: dyslipidemia

Secondary amyloidosis is the most frequent form of the systemic amyloidosis around the world. Data on frequency and nature of dyslipidemia in patients with secondary amyloidosis are not conclusive. We evaluated the lipid abnormalities and their association with clinical and laboratory characteristics of the patients with secondary amyloidosis. The reports of the kidney biopsies performed in our hospital were reviewed. Clinical and laboratory data of the patients with biopsy-proven secondary amyloidosis were analyzed retrospectively. A total of 102 patients were diagnosed as having secondary amyloidosis. Familial Mediterranean fever was the leading cause of secondary amyloidosis accounting for 42.2 % of the cases. The most frequent indication for kidney biopsy was the nephrotic range proteinuria. The most common clinical and laboratory characteristics at the time of the diagnosis were edema, proteinuria and impaired renal function. The frequency of the nephrotic range proteinuria and microscopic hematuria were 75.5 and 18.6 %, respectively. Dyslipidemia was found in 88 % of the cases. Serum lipids significantly correlated with estimated glomerular filtration rate (eGFR), but not with serum albumin or urine protein levels. We demonstrated that majority of the patients with secondary amyloidosis had serum lipid abnormalities. Dyslipidemia was closely associated with GFR in a manner that patients with advanced stage kidney disease had lower serum lipid levels.     

Effectiveness of Endothelial Cell Seeding on Patency of Damaged Vascular Surfaces in a Canine Model

The effects of endothelial cell seeding, which is assumed to be an effective technique to improve patency rates of denuded vascular surfaces, were investigated in an experimental model. In this study, after anesthetic induction, jugular veins of 16 dogs were harvested bilaterally. Endothelial cells were extracted enzymatically by collagenase from these veins and were passaged into a culture medium until they grew to a reasonable number. After 3 weeks, dogs were anesthetized again in a similar fashion and bilateral femoral veins were exposed and experimental intimal denudation was performed. Subsequently, one femoral artery was injected with cell solution and the other with saline solution as a control. Two weeks after the injections, arteriographic studies of femoral arteries were performed and arterial specimens were taken for histological evaluation. Our results suggest that endothelial seeding might improve the patency rate in elective but urgent cases in which endarterectomy, percutaneous transluminal angioplasty, or similar vascular procedures are considered.     

Investigation of Panton-Valentine leukocidin genes and SCCmec types in clinical Staphylococcus aureus isolates from Turkey

Panton-Valentine leukocidin (PVL) is an important virulence determinant of Staphylococcus aureus. The aim of this study was to investigate the prevalence of PVL genes in clinical S. aureus isolates and to determine the staphylococcal chromosomal cassette mec (SCCmec) types of methicillin-resistant S. aureus (MRSA) strains obtained from inpatients and outpatients of two hospitals in Turkey. Of the 304 S. aureus strains (230 hospital acquired [HA] and 74 community-onset [CO]), 261 were MRSA and 43 were methicillin-sensitive S. aureus (MSSA). PVL positivity was determined in 12 (1 HA and 11 community acquired) strains. Eight were MRSA, and four were MSSA. Seven of the PVL-positive strains were isolated from wound specimens, four from urine, and one from synovial fluid. SCCmec type III (93.78%) was more prevalent among HA-MRSA strains, and SCCmec type IIIB (41.18%) was more prevalent among CO-MRSA strains. Pulsed-field gel electrophoresis patterns of the PVL-positive isolates were different. Our results indicate that PVL-positive strains are able to cause infection in nearly every system without the need for additional risk factors. Our PVL-positive CO-MRSA strains carry SCCmec types other than types IV and V. Due to the presence of PVL-positive strains in the hospitals, it is important to establish appropriate infection control measures to prevent their spread in the community and in hospitals.     

Uric Acid is an Important Predictor for Hypertensive Early Atherosclerosis

Introduction  

The association between hyperuricemia and cardiovascular disease in hypertensive subjects is controversial. Attempts to elucidate the possible association between hyperuricemia and early atherosclerosis in hypertensive patients may provide alternative prevention or therapy targets for future cardiovascular events.     

Ambulatory Blood Pressure Monitoring and Echocardiographic Findings in Renal Transplant Recipients

Hypertension is common in renal transplant recipients (RTRs). Ambulatory blood pressure (BP) monitoring (ABPM) is important in diagnosing hypertension and diurnal BP variation. The authors set out to compare office BP and ABPM measurements to determine diurnal pattern and to evaluate echocardiographic findings in RTRs. ABPM and office BP measurements were compared in 87 RTRs. Echocardiographic evaluation was performed for each patient. The correlations between office and 24‐hour ABPM were 0.275 for mean systolic BP (P=.011) and 0.260 for mean diastolic BP (P=.017). Only 36.8% had concordant hypertension between office BP and ABPM, with a masked hypertension rate of 16.1% and white‐coat effect rate of 24.1%. Circadian BP patterns showed a higher proportion of nondippers (67.8%). Left ventricular mass index was increased in 21.8% of all recipients. There was a significant but weak correlation between office BP and ABPM.     

Impact of patient,surgical, and implant design factors on predicted tray–bone interface micromotions in cementless total knee arthroplasty

Micromotion magnitudes exceeding 150 µm may prevent bone formation and limit fixation after cementless total knee arthroplasty (TKA). Many factors influence the tray–bone interface micromotion but the critical parameters and sensitivities are less clear. In this study, we assessed the impacts of surgical (tray alignment, tibial coverage, and resection surface preparation), patient (bone properties and tibiofemoral kinematics), and implant design (tray feature and surface friction) factors on tray–bone interface micromotions during a series of activities of daily living. Micromotion was estimated via three previously validated implant-bone finite element models and tested under gait, deep knee bending, and stair descent loads. Overall, the average micromotion across the tray–bone cementless contact interface ranged from 9.3 to 111.4 µm, and peak micromotion was consistently found along the anterior tray edge. Maximizing tibial coverage above a properly sized tibial tray (an average of 12.3% additional area) had minimal impact on micromotion. A 1 mm anterior tray alignment change reduced the average micromotion by an average of 16.1%. Two-degree tibial angular resection errors reduced the area for bone ingrowth up to 48.1%. Differences on average micromotion from ±25% changes in bone moduli were up to 75.5%. A more posterior tibiofemoral contact due to additional 100 N posterior force resulted in an average of 79.3% increase on average micromotion. Overall, careful surgical technique, patient selection, and controlling kinematics through articular design all contribute meaningfully to minimizing micromotion in cementless TKA, with centralizing the load transfer to minimize the resulting moment at the anterior tray perimeter a consistent theme.     

Two possible cases of Trichosporon infections in bone-marrow-transplanted children: the first case of T. japonicum isolated from clinical specimens

Trichosporon spp. are emerging as opportunistic agents that cause systemic diseases in immunocompromised hosts. Trichosporonosis carries a poor prognosis in neutropenic patients. Trichosporon japonicum was isolated from the air and named by Sugita et al. Here we present the first case of T. japonicum isolated from a clinical specimen. Two cases of acute myeloid leukemia who had Trichosporon isolates are discussed because of their rarity and growing importance. T. asahii was isolated from the throat, feces and urine of the first patient. T. japonicum was isolated from the sputum of the second patient. Both cases produced high MICs to itraconazole, and low MICs to fluconazole and voriconazole. In virulance factor investigations there was (++) biofilm formation in T. japonicum but not in T. asahii. Conventional mycological studies were not adequate for the identification of the isolate at the species level. In our second case as in the first one, the isolate was identified as T. asahii with 99.9% accuracy by API 20C AUX. Although two T. asahii isolates from the same patient yielded identical typing profiles by arbitrary primed-PCR, the isolates of the two different patients showed different arbitrary primed-PCR typing profiles. However, the genetic identification of the other patient's strain gave the result of T. japonicum.